WASHINGTON — It was deja vu all over again at the Supreme Court yesterday, as justices reprised the First Amendment debate over provisions of the federal campaign-finance law that restrict electioneering ads just before an election.

In the 2003 litigation over the law that resulted in the ruling McConnell v. Federal Election Commission, the First Amendment lost, with a majority of the Court upholding the restrictions on their face, even though they restrict speech when it arguably matters most.

Yesterday, presented with a real-life challenge by a Wisconsin antiabortion group that had to yank its advertisements off the air because of the restrictions on electioneering ads, some justices appeared to have second thoughts while others appeared annoyed that the issue was being revisited at all.

“You have a very good argument, but we heard it right in that case,” Justice Stephen Breyer told James Bopp, lawyer for the Wisconsin group, referring to the McConnell decision. “What’s different, or are you asking us to undo what we did?”

Bopp said the ads at issue were examples of “grassroots lobbying” on a legislative issue, which should not be covered by the ban on the broadcast of electioneering ads directly funded by corporations and unions right before elections. “There is more to government than elections,” Bopp said.

Justice Antonin Scalia for his part said the law restricted a “very fundamental guarantee” of free speech, telling Solicitor General Paul Clement, “Maybe you can’t do entirely what you want to do.” Clement was defending the law on behalf of the Federal Election Commission.

But by the end of the hour, it appeared very possible that those second thoughts expressed by Scalia and others will turn into third thoughts; the case may have to be argued yet again.

Retiring Justice Sandra Day O’Connor, probably in her final days on the bench, participated in yesterday's arguments in Wisconsin Right to Life Inc. v. Federal Election Commission. She was the key fifth vote in favor of the restrictions in 2003, but if she leaves the Court before it issues its ruling — as appears almost certain — the Court could divide 4-4. It could leave that tie vote in place, which would let stand the lower court decision favoring the law. Or it could schedule a new round of arguments in the case once nominee Samuel Alito Jr., whose confirmation is expected, takes his seat.

The case argued yesterday was an inevitable outgrowth of the McConnell decision, which assessed the Bipartisan Campaign Reform Act in the abstract, before anyone actually harmed by the law had a chance to sue. But such a ruling would ordinarily leave the door open to “as-applied” challenges — disputes that would display real-life problems showing how the law was affecting actual campaign speakers.

Wisconsin Right to Life, a nonprofit corporation, used its funds in 2004 to run broadcast ads urging both of that state’s senators, Russ Feingold and Herb Kohl, not to filibuster President Bush’s judicial nominees. But because Feingold was running for reelection and the ads mentioned him by name, airing them within 60 days before the fall election would violate the campaign-finance law, even though the ads did not urge listeners to vote for or against Feingold.

Just before the 60-day mark, the Wisconsin group challenged the law in court, but was rebuffed. A three-judge panel ruled that McConnell precluded “as-applied” challenges such as that filed by Wisconsin Right to Life.

In yesterday's oral arguments, Chief Justice John Roberts Jr. rebuked Solicitor General Paul Clement for taking the same position against as-applied challenges. Roberts, who once served in the solicitor general’s office, said the government’s position amounted to “classic bait and switch,” because during the McConnell litigation the government indicated as-applied challenges would be possible.

Clement indicated in response that McConnell was one of those decisions that is definitive enough that they leave no room for as-applied challenges.

But Roberts replied that First Amendment cases were different, implying that as-applied challenges should generally be permitted. If Roberts votes against the government, he would mirror the position of his predecessor William Rehnquist.

Clement said that because it is difficult to categorize slightly differing kinds of ads, “you need a bright-line rule.”

The ads in question, Clement said, would have been permitted had they not mentioned candidate Feingold by name or if they had been funded by the Wisconsin group’s more closely regulated political action committee. That PAC had targeted Feingold as a candidate who should be defeated.

Justice Anthony Kennedy voiced concern that the law requires government to examine an organization’s “ideological pedigree” and bases its restrictions on the content of the advertising, both features objectionable under the First Amendment.